Waiting for exhale

Wednesday

BOSTON — A new method for analyzing the hormones found when a whale expels air could be a leap forward in understanding the health of the species, according to a report released Tuesday.

“We know we can detect hormones, but we haven’t been able to quantify them,” said lead author Elizabeth Burgess, an associate scientist with the Anderson Cabot Center for Ocean Life at New England Aquarium.

The 2015 study of 46 North Atlantic right whales was conducted in eight days along the East Coast, generally along the migratory path of the whales. The results were published in the journal Scientific Reports.

Accurately measuring hormones in whale blow — the spray released when a whale exhales — can signal if the animal is under stress or pregnant, Burgess said.

"It's an important advance," said Provincetown-based Center for Coastal Studies right whale expert Charles "Stormy" Mayo of the technique. But he added that identifying a problem is only half the battle. "If there is a hormonal deficiency, what would we do?" he said. "If the animal is not getting enough food, is there anything we can do to enrich the western North Atlantic Ocean?"

Right whales, in particular, have undergone a worrisome decline in population since 2010. Last year was an especially bad year, scientists say, with 17 documented deaths in the Gulf of St. Lawrence in Canada and off Cape Cod, compounded with the lack of any known calves in the most recent birthing season.

Scientists previously have studied hormone levels in whale feces, which has helped show how whales respond to stress, physical injury and reproductive capabilities. But collecting scat requires researchers to be in an area where whales are feeding and to wait for a defecation, both of which are less predictable than finding a whale exhaling, Burgess said.

“For the first time, we don’t have to wait around for these whales to poop,” said Scott Kraus, center vice-president and senior science adviser.

The 100 samples taken from whale spouts were captured by scientists on a research vessel holding a 32-foot-long pole over a whale blowhole with a petri dish or mesh nylon fabric to collect the spray. A right whale whale known to be pregnant, named Harmonia, helped the scientists prove their concept after hormone samples taken from blows and from a fecal sample showed similar, high levels of progesterone, which is characteristic of pregnancy.

The gathering and analysis of hormones in whale blow is relatively harmless and avoids invasive interactions with whales, and provides a real-time snapshot of aspects of the whale’s health, Burgess said. “Similar to a (human) blood sample,” she said.

In the future, the technique will need to be refined and tested, the report stated. The method could be used to detect early warning signs in whale populations before high mortality counts or low calving rates appear, Burgess said.

"This is an excellent, careful study of an important aspect of large whale health, at individual, population and species levels," said Woods Hole Oceanographic Institution biologist Michael Moore, who directs the facility's Marine Mammal Center.

Moore and other scientists at Woods Hole have focused on whale blow as well, with the use of drones.

Last October, the institution published a paper about research of 26 blow samples of humpback whales in 2015 at Stellwagen Bank National Marine Sanctuary, north of Provincetown, and in 2016 in waters off Washington state and British Columbia. The study showed 25 microorganisms in common across all the whale blows sampled. That study showed that different humpback populations — one East Coast and one West Coast — harbor similar microbial communities in their blow, including the presence of a large number of “core bacteria” shared between all individuals.

Of those 25 microorganisms common to the respiratory tract of two populations of humpback whales, about 20 are linked with marine mammals from previous studies, which suggests that grouping is specialized to marine mammals and may indicate a healthy, noninfected pulmonary system, according to the report. In assessing the health of whales, any alterations to and absences from that core whale blow “microbiome” could be an indicator of pulmonary infections and diseases.

The researchers attached a sterilized petri dish to the top of the hexacopter to collect the whale blow.

The information could help with monitoring of humpback health and possibly other large animals, according to the report.

—Follow Mary Ann Bragg on Twitter: @maryannbraggCCT.

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